Abstract

The syntheses of enantiomeric threo- and erythro-1,2-diamino-1-phenylpropanes (Ph/Me) and of racemic 1,2-diaminophenylethane (Ph/H) are described. These diamines and related N2-methyl- and N1,N2-dimethyl-1,2-diamino-1-phenylpropanes were transformed into dichloroplatinum(II) complexes I [R1 = R2 = R3 = H (Ph/H-PtCl2); R1 = Me, R2 = R3 = Me (Ph/Me-PtCl2); R1 = R3 = Me, R2 = H (Ph/Me-Me-PtCl2); R1 = R2 = R3 = Me (Ph/Me-Dime-PtCl2)]. For the 1H NMR spectroscopic detn. of their optical purity the diamines (Ph/Me) were converted with (R)-myrtenal into their diimines. In the test on the MCF-7 breast cancer cell line (R,R)-Ph/Me-PtCl2 produced the strongest effect of all new complexes, comparable with that of the std. cisplatin and of other Pt complexes. Its enantiomer (S,S)-Ph/Me-PtCl2 possessed a distinctly weaker inhibitory potency while the erythro-configurated counterparts were even less active [(R,R)>(S,S)>(S,R) = (R,S)]. All N2-methylated and N1,N2-dimethylated complexes (Ph/Me-Me-PtCl2, Ph/Me-Dime-PtCl2) showed comparable activities equaling those of (R,S)- and (S,R)-Ph/Me-PtCl2. The mol. reasons for the differing potencies of the diastereomeric and enantiomeric Ph/Me-PtCl2 complexes are discussed in consideration of the complex conformation.